/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package com.sun.org.apache.bcel.internal.classfile;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import com.sun.org.apache.bcel.internal.Constants;
import java.io.*;

/**
 * This class represents the table of exceptions that are thrown by a
 * method. This attribute may be used once per method.  The name of
 * this class is <em>ExceptionTable</em> for historical reasons; The
 * Java Virtual Machine Specification, Second Edition defines this
 * attribute using the name <em>Exceptions</em> (which is inconsistent
 * with the other classes).
 *
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @see     Code
 */
public final class ExceptionTable extends Attribute {
    private int number_of_exceptions; // Table of indices into
    private int[] exception_index_table; // constant pool

    /**
     * Initialize from another object. Note that both objects use the same
     * references (shallow copy). Use copy() for a physical copy.
     */
    public ExceptionTable(ExceptionTable c) {
        this(c.getNameIndex(), c.getLength(), c.getExceptionIndexTable(), c.getConstantPool());
    }

    /**
     * @param name_index Index in constant pool
     * @param length Content length in bytes
     * @param exception_index_table Table of indices in constant pool
     * @param constant_pool Array of constants
     */
    public ExceptionTable(int name_index, int length, int[] exception_index_table, ConstantPool constant_pool) {
        super(Constants.ATTR_EXCEPTIONS, name_index, length, constant_pool);
        setExceptionIndexTable(exception_index_table);
    }

    /**
     * Construct object from file stream.
     * @param name_index Index in constant pool
     * @param length Content length in bytes
     * @param file Input stream
     * @param constant_pool Array of constants
     * @throws IOException
     */
    ExceptionTable(int name_index, int length, DataInputStream file, ConstantPool constant_pool) throws IOException {
        this(name_index, length, (int[]) null, constant_pool);

        number_of_exceptions = file.readUnsignedShort();
        exception_index_table = new int[number_of_exceptions];

        for (int i = 0; i < number_of_exceptions; i++)
            exception_index_table[i] = file.readUnsignedShort();
    }

    /**
     * Called by objects that are traversing the nodes of the tree implicitely
     * defined by the contents of a Java class. I.e., the hierarchy of methods,
     * fields, attributes, etc. spawns a tree of objects.
     *
     * @param v Visitor object
     */
    public void accept(Visitor v) {
        v.visitExceptionTable(this);
    }

    /**
     * Dump exceptions attribute to file stream in binary format.
     *
     * @param file Output file stream
     * @throws IOException
     */
    public final void dump(DataOutputStream file) throws IOException {
        super.dump(file);
        file.writeShort(number_of_exceptions);
        for (int i = 0; i < number_of_exceptions; i++)
            file.writeShort(exception_index_table[i]);
    }

    /**
     * @return Array of indices into constant pool of thrown exceptions.
     */
    public final int[] getExceptionIndexTable() {
        return exception_index_table;
    }

    /**
     * @return Length of exception table.
     */
    public final int getNumberOfExceptions() {
        return number_of_exceptions;
    }

    /**
     * @return class names of thrown exceptions
     */
    public final String[] getExceptionNames() {
        String[] names = new String[number_of_exceptions];
        for (int i = 0; i < number_of_exceptions; i++)
            names[i] = constant_pool.getConstantString(exception_index_table[i], Constants.CONSTANT_Class).replace('/', '.');
        return names;
    }

    /**
     * @param exception_index_table.
     * Also redefines number_of_exceptions according to table length.
     */
    public final void setExceptionIndexTable(int[] exception_index_table) {
        this.exception_index_table = exception_index_table;
        number_of_exceptions = (exception_index_table == null) ? 0 : exception_index_table.length;
    }

    /**
     * @return String representation, i.e., a list of thrown exceptions.
     */
    public final String toString() {
        StringBuffer buf = new StringBuffer("");
        String str;

        for (int i = 0; i < number_of_exceptions; i++) {
            str = constant_pool.getConstantString(exception_index_table[i], Constants.CONSTANT_Class);
            buf.append(Utility.compactClassName(str, false));

            if (i < number_of_exceptions - 1)
                buf.append(", ");
        }

        return buf.toString();
    }

    /**
     * @return deep copy of this attribute
     */
    public Attribute copy(ConstantPool constant_pool) {
        ExceptionTable c = (ExceptionTable) clone();
        c.exception_index_table = (int[]) exception_index_table.clone();
        c.constant_pool = constant_pool;
        return c;
    }
}
